As climate change drives more extreme weather and rising seas, nearly one in five people globally face serious flood risk. WaveSave, a Dutch startup, makes a portable rubber dam called SlamDam that can be unrolled along a riverbank or shoreline and filled with water using any available pump. Within hours, it swells into a barrier up to 1.3 meters tall, protecting homes, farms, hospitals, and other critical facilities from floodwaters.
SlamDam was developed in the Netherlands in 2013 and has since been deployed in at least a dozen countries across Europe, Africa, and Southeast Asia. It is also being tested on New York City's Governors Island. One notable benefit: after a flood, the water stored inside the dam can be tapped for irrigation. In Burundi's Mpanda commune, farmers who used that stored water doubled their incomes during the 2022 flood season, according to a UN report.
Still, adoption is not always smooth. A research team studying SlamDam's use in Kenya found challenges around who should own and deploy the dam, as well as its upfront cost. A five-meter section costs between €1,000 and €3,000, which is too expensive for many communities. WaveSave's managing director says the company is exploring offering the dam as a service and plans to open local production facilities in Southeast Asia and East Africa to reduce costs. The company also aims to expand into broader water-management services, such as rainwater harvesting and irrigation advice, as part of a more comprehensive approach to climate resilience.